1. Field of the Invention
This invention relates to a new intermittent patient suction system and to a new self-contained control device therefor as well as to new methods for respectively making the new system and the new control device.
2. Prior Art Statement
It is known to provide an intermittent suction system having output means for alternately applying a vacuum and atmospheric pressure to a patient for removing fluids from the patient and wherein the system includes a vacuum source and first and second container means adapted to be interconnected to operating means of a self-contained control device and to the source and the atmospheric pressure by the operating means of the control device that is adapted to apply the vacuum through the output means to the patient in response to a vacuum condition of the first container means and to apply the atmospheric pressure through the output means to the patient in response to a vacuum condition in the second container means, the operating means of the control device having means for always interconnecting the vacuum through the output means to the patient when the vacuum condition in the first container means is a certain percentage of the source regardless of the vacuum value of the source so as to prevent any adverse interruption in the system during the use thereof for the patient should the vacuum level of the source fall to an undesirable level, the control device having a housing means, and two adjustable restrictor means for respectively controlling the "on" time and "off" time that the control device applies the vacuum and does not apply the vacuum through the output means to the patient. For example, see the U.S. patent to Lewis, U.S. Pat. No. 4,213,457.
It was suggested by another that perhaps the self-contained control device as set forth in the aforementioned U.S. patent to Lewis, U.S. Pat. No. 4,213,457, could be modified so that such restrictor means thereof, as well as a third restrictor means that controls the flow through the output means, could be disposed in the housing means of the control device so as to be carried thereby. However, such suggestion did not provide any information as to how the physical structure of the restrictor means could be incorporated into a self-contained control device nor how the flow passages of such system within the control device should be modified to accommodate such restrictor means.
Accordingly, applicant then invented the unique arrangement as set forth in FIGS. 1-4.
Subsequent to such arrangement of FIGS. 1-4 having been invented by applicant, it was again suggested by another that perhaps the adjustable restriction means R1 and R2 thereof could be fixed restriction means rather than adjustable restriction means. However, again such suggestion did not provide any information as to how the physical structure of the adjustable restrictor means could be changed nor what new structure should be provided to have fixed restrictor means.
Therefore, applicant then invented the unique arrangement as set forth in FIGS. 5 and 6.
Another intermittent patient suction system is set forth in the U.S. patent to Sielaff, U.S. Pat. No. 3,659,605.